Several applications can be envisioned wherein a projectile needs to be quickly accelerated from standstill to a very high velocity (e.g. 3-5 km/sec). For such applications, there are, obviously, certain constraints that require special consideration. For instance, when the acceleration path of the particle is curved, as opposed to being straight, centrifugal acceleration forces are created on the projectile. These forces then present additional constraints for consideration. In particular, any limitations the centrifugal acceleration forces may impose on the acceleration of the projectile must be evaluated. Even when a straight acceleration path is available, access to the path may become a significant concern. Add to this other considerations, such as a need to accelerate a series of projectiles at a high repetition rate, and a need to achieve reliable acceleration, and it becomes clear that each application requires special consideration.
As implied above, for specific instances wherein a projectile must be moved along a path that necessarily includes curves, the tortuous nature of the path can severely limit velocity of the projectile. Of particular concern regarding the acceleration of projectiles is the ability to fuel a plasma using projectiles (i.e. fuel pellets). It happens, however, that for several reasons, the use of fuel pellets for this purpose may be very desirable. Indeed, it is a standard practice to fuel various types of plasma confinement devices by injecting frozen hydrogenic pellets into the plasma chamber.
It is also well known that toroidally shaped plasma confinement devices are more efficiently fueled, if the fuel can be delivered into the plasma from its (high field side) inner wall. To do this, however, fuel pellets typically need to travel from outside the plasma confinement device and into the plasma. This may require the pellet to travel along a path that is quite tortuous. Nevertheless, in order to ensure good plasma penetration by the fuel pellets, and to have density control flexibility, it is still necessary that the fuel pellet be injected into the plasma at very high velocities. Heretofore, the practice has been to rely on whatever velocity can be practicably attained when acceleration of the pellet is accomplished before the pellet enters the plasma confinement device.
In light of the above, it is an object of the present invention to provide systems and methods for accelerating projectiles (fuel pellets), wherein the pellet is moved at a relatively low velocity until the pellet is in position for rapid acceleration and injection into the plasma chamber of the plasma confinement device. Another object of the present invention is to provide systems and methods for accelerating projectiles (fuel pellets) wherein a propulsion force on the pellet is initiated using microwave energy. Still another object of the present invention is to provide systems and methods for accelerating projectiles (fuel pellets) that are easy to use, are relatively simple to operate, and are comparatively cost effective.